Type 2 Diabetes – Canadian Task Force on Preventive Health Care

Guideline Update

The guideline has been updated to incorporate the latest evidence from a large randomized controlled trial that was published on October 4, 2012—two weeks before publication of the print issue.

Although the electronic version of the CTFPHC guideline that is available on the Canadian Medical Association Journal (CMAJ) website is correct, the version that was included in the print issue of CMAJ on October 16, 2012 was already at the printers when the new trial was released and is now outdated.

A corrected reprint was mailed to CMAJ subscribers on November 6, 2012.

Summary of recommendations for clinicians and policy-makers

Recommendations are presented for screening asymptomatic adults for type 2 diabetes. They do not apply to people with symptoms of diabetes or those at risk of type 1 diabetes.

The CTFPHC will continue to carefully monitor the scientific development in diabetes screening and report back to Canadians within 5 years with an update of the 2012 Diabetes Screening guideline.

Recommendations

For adults at low to moderate risk of diabetes (determined with a validated risk calculator
^Note Risk calculation for 10-year risk for diabetes:
Low Risk: 1 ÷ 100 to 1 ÷ 25 = 1% to 4%
Moderate Risk: 1 ÷ 6 = 17%
High Risk: 1 ÷ 3 = 33%
Very High Risk: 1 ÷ 2 = 50%
For adults ≥ 18 years of age, we suggest risk calculation at least every 3–5 years (when risk factors exist (e.g., obesity & hypertension).

^Note FINDRISC (the Finnish Diabetes Risk Score) has been selected as the preferred validated risk calculator, but CANRISK (the Canadian Diabetes Risk Questionnaire) is an acceptable alternative. Factors considered in FINDRISC and CANRISK are age, obesity, history of elevated glucose levels, history of hypertension, family history of diabetes, limited activity levels, and diet with limited intake of fruits and vegetables. The CANRISK questionnaire can be found on the CTFPHC website or on the PHAC website.
), we recommend not routinely screening for type 2 diabetes.
(Weak recommendation; low-quality evidence)
For adults at high risk of diabetes (determined with a validated risk calculator
^Note Risk calculation for 10-year risk for diabetes:
Low Risk: 1 ÷ 100 to 1 ÷ 25 = 1% to 4%
Moderate Risk: 1 ÷ 6 = 17%
High Risk: 1 ÷ 3 = 33%
Very High Risk: 1 ÷ 2 = 50%
For adults ≥ 18 years of age, we suggest risk calculation at least every 3–5 years (when risk factors exist (e.g., obesity & hypertension).

^Note FINDRISC (the Finnish Diabetes Risk Score) has been selected as the preferred validated risk calculator, but CANRISK (the Canadian Diabetes Risk Questionnaire) is an acceptable alternative. Factors considered in FINDRISC and CANRISK are age, obesity, history of elevated glucose levels, history of hypertension, family history of diabetes, limited activity levels, and diet with limited intake of fruits and vegetables. The CANRISK questionnaire can be found on the CTFPHC website or on the PHAC website.
), we recommend routinely screening every 3–5 years with A1C
^Note A1C has been selected as the preferred blood test, but fasting glucose measurement and the oral glucose tolerance test are acceptable alternatives. An A1C level of 6.5% or greater is recommended as the threshold for diagnosing diabetes, but values less than 6.5% do not exclude diabetes diagnosed using glucose tests. A1C should be measured using a standardized, validated assay.
.
(Weak recommendation; low-quality evidence)
For adults at very high risk of diabetes (determined with a validated risk calculator
^Note Risk calculation for 10-year risk for diabetes:
Low Risk: 1 ÷ 100 to 1 ÷ 25 = 1% to 4%
Moderate Risk: 1 ÷ 6 = 17%
High Risk: 1 ÷ 3 = 33%
Very High Risk: 1 ÷ 2 = 50%
For adults ≥ 18 years of age, we suggest risk calculation at least every 3–5 years (when risk factors exist (e.g., obesity & hypertension).

^Note FINDRISC (the Finnish Diabetes Risk Score) has been selected as the preferred validated risk calculator, but CANRISK (the Canadian Diabetes Risk Questionnaire) is an acceptable alternative. Factors considered in FINDRISC and CANRISK are age, obesity, history of elevated glucose levels, history of hypertension, family history of diabetes, limited activity levels, and diet with limited intake of fruits and vegetables. The CANRISK questionnaire can be found on the CTFPHC website or on the PHAC website.
), we recommend routine screening annually with A1C
^Note A1C has been selected as the preferred blood test, but fasting glucose measurement and the oral glucose tolerance test are acceptable alternatives. An A1C level of 6.5% or greater is recommended as the threshold for diagnosing diabetes, but values less than 6.5% do not exclude diabetes diagnosed using glucose tests. A1C should be measured using a standardized, validated assay.
.
(Weak recommendation; low-quality evidence)

&nbsp

Additional Documents

Category : Published

Date : 16 Oct 2012